They seem biased to me. A friend of mine who's doing an ICO told me that they paid 10ETH for 5 quality ratings and that's that! I noticed that some ICOs with good project, team, and good social media presence are struggling with getting good reviews.
With all that said, should it still be a factor to look at when investing in ICO?
True! I don't trust rating sites. I just use them to see if there are really interesting ICO's that are forthcoming.
I ask a lot in their Telegram community to do my own research.